1. Field of the Invention
Embodiments of the present invention generally relate to processing systems and methods of operating thereof. Particularly, they relate to utilization of process chambers in a processing system, e.g., for multi-layer stack deposition. Specifically they relate to a substrate processing system and a method of depositing a layer stack in a substrate processing system
2. Description of the Related Art
In a number of technical applications layers of different materials are deposited onto each other over a substrate. Typically, this is done in a sequence of coating or deposition steps, wherein other processing steps like etching or structuring might also be provided before, between, or after the various deposition steps. For example, a multi-layer stack with a sequence of “material one”-“material two”-“material one” can be deposited. Due to different coating rates in different process steps and due to different thicknesses of the layers, the processing time in the processing chambers for depositing different layers may vary considerably.
In order to deposit a multiple layer stack, a number of configurations of processing chambers can be provided. For example, in-line arrangements of deposition chambers can be used as well as cluster arrangements of deposition chambers. A typical cluster arrangement comprises a central handling chamber and a number of processing or deposition chambers connected thereto. The coating chambers may be equipped to carry out the same or different processes. A typical in-line system includes a number of subsequent processing chambers, wherein processing steps are conducted in one chamber after the other such that a plurality of substrates can continuously or quasi-continuously be processed with the in-line system. However, whereas the handling of the process in in-line systems is quite easy, the processing time is determined by the longest processing time. Therefore, the efficiency of the process is affected. Cluster tools, on the other hand, allow for different cycle times. However, the handling may be quite complex, which requires an elaborate transfer system provided in the central handling chamber.
The above disadvantages of an in-line system could be compensated for by providing additional chambers. However, this would increase the cost of the equipment, which can be particularly relevant if expensive materials are deposited.